:root {
  color-scheme: light dark;
  --accent: #d7ff3f;
  --accent-ink: #172000;
  --background: #f3f4ef;
  --surface: #e8eae2;
  --surface-strong: #dfe2d8;
  --ink: #151713;
  --muted: #5e6258;
  --line: #c6cabf;
  --danger: #b52c3c;
  --danger-surface: #f9d8dd;
  --success: #246b40;
  --success-surface: #d8f0df;
  --focus: #356fdb;
  --radius-panel: 18px;
  --radius-control: 12px;
  --shadow: 0 24px 70px rgba(45, 53, 35, 0.12);
  --font: Arial, "Helvetica Neue", sans-serif;
  --font-display: "Arial Black", Arial, "Helvetica Neue", sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --background: #151713;
    --surface: #20231d;
    --surface-strong: #2a2e26;
    --ink: #f2f4ec;
    --muted: #b2b8a9;
    --line: #444a3e;
    --danger: #ff8a98;
    --danger-surface: #48232a;
    --success: #8ce0a6;
    --success-surface: #183d25;
    --focus: #91b8ff;
    --shadow: 0 24px 70px rgba(0, 0, 0, 0.28);
  }
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--background);
}

body {
  min-width: 320px;
  min-height: 100dvh;
  margin: 0;
  background:
    radial-gradient(circle at 90% 8%, color-mix(in srgb, var(--accent) 18%, transparent), transparent 26rem),
    var(--background);
  color: var(--ink);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.5;
  text-rendering: optimizeLegibility;
}

button,
input {
  font: inherit;
}

button,
a,
input {
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
}

button {
  min-height: 48px;
}

.app-shell {
  width: min(100%, 1120px);
  min-height: 100dvh;
  margin: 0 auto;
  padding: max(18px, env(safe-area-inset-top)) clamp(18px, 4vw, 48px) max(18px, env(safe-area-inset-bottom));
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.site-header,
.site-footer {
  min-height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.wordmark {
  display: inline-flex;
  align-items: center;
  padding: 7px 10px;
  border-radius: 10px;
  background: #1b1b1c;
  text-decoration: none;
}

.wordmark img {
  display: block;
  width: clamp(106px, 25vw, 127px);
  height: auto;
}

.session-name,
.site-footer {
  color: var(--muted);
  font-size: 0.875rem;
}

.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 20px;
  padding-top: 14px;
}

.site-footer a {
  color: inherit;
}

.app-main {
  min-height: min(720px, calc(100dvh - 150px));
  display: grid;
  place-items: center;
  padding-block: clamp(24px, 5vw, 60px);
}

.app-main:focus {
  outline: none !important;
}

.view {
  width: 100%;
  animation: view-in 360ms cubic-bezier(0.16, 1, 0.3, 1) both;
}

.start-view {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.6fr);
  gap: clamp(32px, 8vw, 100px);
  align-items: end;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.display-title {
  max-width: 760px;
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(3.4rem, 9vw, 8.5rem);
  letter-spacing: -0.075em;
  line-height: 0.84;
}

.display-title .avoid-word {
  color: transparent;
  -webkit-text-stroke: 2px var(--ink);
}

.intro-copy {
  max-width: 30ch;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(1rem, 2vw, 1.2rem);
}

.start-form {
  border: 1px solid var(--line);
  border-radius: var(--radius-panel);
  background: color-mix(in srgb, var(--surface) 90%, transparent);
  box-shadow: var(--shadow);
  padding: clamp(22px, 4vw, 34px);
}

.field {
  display: grid;
  gap: 8px;
}

.field label {
  font-weight: 700;
}

.field input {
  width: 100%;
  min-height: 52px;
  border: 1px solid var(--line);
  border-radius: var(--radius-control);
  background: var(--background);
  color: var(--ink);
  padding: 12px 14px;
}

.field input::placeholder {
  color: color-mix(in srgb, var(--muted) 90%, transparent);
}

.field-error {
  min-height: 1.4em;
  margin: 4px 0 0;
  color: var(--danger);
  font-size: 0.9rem;
}

.privacy-note {
  margin: 16px 0 20px;
  color: var(--muted);
  font-size: 0.82rem;
}

.primary-button,
.secondary-button,
.answer-button,
.text-button {
  border: 0;
  border-radius: var(--radius-control);
  cursor: pointer;
  font-weight: 800;
  transition: transform 160ms ease, background-color 160ms ease, color 160ms ease, border-color 160ms ease;
}

.primary-button {
  width: 100%;
  background: var(--accent);
  color: var(--accent-ink);
  padding: 14px 18px;
}

.secondary-button {
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  padding: 13px 18px;
}

.text-button {
  min-height: 44px;
  background: transparent;
  color: var(--ink);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.primary-button:hover,
.primary-button:active,
.secondary-button:hover,
.secondary-button:active,
.answer-button:hover,
.answer-button:active {
  transform: translateY(-1px);
}

.primary-button:active,
.secondary-button:active,
.answer-button:active {
  transform: scale(0.98);
}

button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
  transform: none;
}

.game-view {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
}

.game-topline {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 24px;
  align-items: center;
}

.card-counter {
  margin: 0;
  font-weight: 700;
}

.progress-dots {
  display: grid;
  grid-template-columns: repeat(15, minmax(4px, 1fr));
  gap: 5px;
  margin-top: 12px;
}

.progress-dots span {
  height: 5px;
  border-radius: 5px;
  background: var(--line);
}

.progress-dots span.is-done,
.progress-dots span.is-current {
  background: var(--accent);
}

.progress-dots span.is-current {
  transform: scaleY(1.8);
}

.timer {
  --timer-progress: 1;
  width: 88px;
  aspect-ratio: 1;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: conic-gradient(var(--accent) calc(var(--timer-progress) * 1turn), var(--surface-strong) 0);
  position: relative;
  font-family: var(--font-display);
  font-size: 2rem;
}

.timer::before {
  content: "";
  position: absolute;
  inset: 8px;
  border-radius: inherit;
  background: var(--background);
}

.timer span {
  position: relative;
}

.question-panel {
  min-height: clamp(310px, 48dvh, 520px);
  border-radius: var(--radius-panel);
  background: var(--surface);
  padding: clamp(28px, 7vw, 72px);
  display: grid;
  align-content: space-between;
  gap: 40px;
  box-shadow: var(--shadow);
}

.question-text {
  max-width: 25ch;
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2rem, 5.6vw, 4.8rem);
  letter-spacing: -0.055em;
  line-height: 0.98;
}

.answer-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.answer-button {
  min-height: 70px;
  border: 2px solid var(--ink);
  background: var(--background);
  color: var(--ink);
  padding: 16px;
  font-family: var(--font-display);
  font-size: clamp(1.2rem, 3vw, 2rem);
}

.answer-button:hover {
  background: var(--ink);
  color: var(--background);
}

.feedback-view {
  max-width: 900px;
  margin-inline: auto;
}

.feedback-panel {
  min-height: min(650px, 72dvh);
  border-radius: var(--radius-panel);
  padding: clamp(28px, 7vw, 70px);
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 36px;
  box-shadow: var(--shadow);
}

.feedback-panel.is-correct {
  background: var(--success-surface);
}

.feedback-panel.is-incorrect {
  background: var(--danger-surface);
}

.feedback-status {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 0;
  font-weight: 800;
}

.feedback-icon {
  width: 48px;
  height: 48px;
  border: 2px solid currentColor;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 1.6rem;
}

.feedback-panel.is-correct .feedback-status {
  color: var(--success);
}

.feedback-panel.is-incorrect .feedback-status {
  color: var(--danger);
}

.principle-label {
  margin: 0 0 12px;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.feedback-principle {
  max-width: 22ch;
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2rem, 6vw, 5rem);
  letter-spacing: -0.06em;
  line-height: 0.96;
}

.feedback-copy {
  max-width: 50ch;
  margin: 22px 0 0;
  font-size: clamp(1rem, 2vw, 1.25rem);
}

.correct-answer {
  color: var(--muted);
  font-weight: 700;
}

.feedback-actions {
  display: flex;
  justify-content: flex-end;
}

.feedback-actions .primary-button {
  width: auto;
  min-width: 160px;
}

.result-view {
  display: grid;
  gap: clamp(34px, 7vw, 70px);
}

.result-hero {
  display: grid;
  grid-template-columns: minmax(220px, 0.65fr) minmax(0, 1.35fr);
  align-items: end;
  gap: clamp(30px, 8vw, 100px);
}

.score-number {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(5rem, 18vw, 12rem);
  letter-spacing: -0.09em;
  line-height: 0.75;
}

.score-total {
  color: var(--muted);
  font-size: 0.45em;
}

.result-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2.3rem, 6vw, 5.5rem);
  letter-spacing: -0.065em;
  line-height: 0.95;
}

.takeaway {
  max-width: 48ch;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 1.05rem;
}

.result-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.result-actions .primary-button,
.result-actions .secondary-button {
  width: auto;
  min-width: 160px;
}

.review-section h2 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 3rem);
  letter-spacing: -0.045em;
}

.review-list {
  display: grid;
  gap: 10px;
}

.review-item {
  border: 1px solid var(--line);
  border-radius: var(--radius-control);
  background: var(--surface);
  overflow: hidden;
}

.review-item summary {
  min-height: 56px;
  padding: 16px 18px;
  cursor: pointer;
  font-weight: 800;
}

.review-body {
  padding: 0 18px 18px;
}

.review-body p {
  margin: 8px 0;
}

.empty-review {
  border-radius: var(--radius-control);
  background: var(--success-surface);
  color: var(--success);
  padding: 20px;
  font-weight: 800;
}

.loading-view,
.error-view {
  width: min(100%, 620px);
}

.loading-view {
  display: grid;
  gap: 14px;
}

.skeleton {
  border-radius: var(--radius-control);
  background: var(--surface);
  animation: skeleton-pulse 1.2s ease-in-out infinite alternate;
}

.skeleton-short {
  width: 120px;
  height: 18px;
}

.skeleton-title {
  width: 85%;
  height: 96px;
}

.skeleton-body {
  width: 70%;
  height: 28px;
}

.skeleton-button {
  width: 220px;
  height: 54px;
  margin-top: 20px;
}

.error-panel {
  border: 1px solid var(--danger);
  border-radius: var(--radius-panel);
  background: var(--danger-surface);
  padding: 28px;
}

.error-panel h1 {
  margin: 0 0 10px;
  font-family: var(--font-display);
}

@keyframes view-in {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes skeleton-pulse {
  to {
    opacity: 0.5;
  }
}

@media (max-width: 767px) {
  .app-shell {
    padding-inline: 16px;
  }

  .app-main {
    min-height: calc(100dvh - 148px);
    padding-block: 24px;
  }

  .start-view,
  .result-hero {
    grid-template-columns: 1fr;
    align-items: start;
  }

  .display-title {
    font-size: clamp(3.5rem, 21vw, 6.8rem);
  }

  .start-form {
    padding: 22px;
  }

  .game-topline {
    grid-template-columns: 1fr 76px;
    gap: 16px;
  }

  .timer {
    width: 76px;
    font-size: 1.7rem;
  }

  .question-panel {
    min-height: min(470px, 58dvh);
    padding: 28px 22px 22px;
    gap: 28px;
  }

  .question-text {
    font-size: clamp(1.7rem, 8.6vw, 3rem);
  }

  .answer-button {
    min-height: 64px;
    font-size: 1.25rem;
  }

  .feedback-panel {
    min-height: min(600px, 70dvh);
    padding: 26px 22px;
  }

  .feedback-actions .primary-button,
  .result-actions .primary-button,
  .result-actions .secondary-button {
    width: 100%;
  }

  .site-footer span {
    display: none;
  }

  .site-footer {
    justify-content: flex-end;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}